This invention concerns a method and an apparatus for recognising and determining the position of at least one teat of a milking animal in accordance with the preambles of claim 1 and 9 respectively. The invention also concerns a robot including such an apparatus.
Such an apparatus is described in WO96/20587. This document concerns solving problems arising from teats of the animal not being in the same position in a subsequent visit as in a previous visit. Such a shift in the position of the teats in particular occurs in case of young animals where the sizes of the udders increase with growths, resulting in greater distances between the teats.
In case of adult animals it has been found that teat positions vary depending on varying milk productivity and time period passing between the visits to the milking robot. In WO96/20587 the actual teat position is constantly checked and the position values are amended on the basis of deviations with respect to previous positions. According to this document, however, the position of the teats of an animal, which is to be milked for the first time, is recorded by the teat cups being moved by hand to the teats of the udder and fixed thereon. The positions are recorded in various memories.
At subsequent milking operations the present images are compared with stored values so as to determine possible changes in position. In the event of such changes, the stored values are replaced with new image values.
The method according to WO96/20587 suffers from the drawback that new animals have to be introduced into the system by manual recording by the farmer of the positions for the teat or teats. This is a time-consuming procedure, which is detrimental for the over all economy of the milk production at the farm. Further, although the prior art system takes account of minor position changes of the teats, it presupposes relatively stable fixing of the animal as much as possible in the same position as the original one in order to be reliable. Major changes of the position of the cow, and in particular of the teats, result in risk of failure to detect the positions of the teats. WO96/20587 speculates in determining the initial position by other methods than the manual method described in that document. The document is however, silent about how to carry out such alternative methods.
It is an object of the invention to provide a method and an apparatus wherein the said drawbacks are eliminated. This aim is obtained in a method and an apparatus as above through the features of the characterizing portions of claim 1 and 9, respectively.
This way a system is provided, which is capable of taking care of practically all new milking animals with respect to introducing them into the system in an automatic manner, with out the farmer having to manually position the teat cups for teaching the system the positions of the teats. By having an initial position, which is chosen such that all relevant animals can be monitored and by moving the scanning head in steps during scanning and finally comparing the subsequent images with each other instead of only with reference images of the like, a safe and reliable system is created. No pre-information is thus needed in order to find the teats of any cow. The system is therefore xe2x80x9cself learningxe2x80x9d.
The inventive system has the capability of recognising and determining teat positions for practically all relevant milking animals, almost irrespective of where the udder is located on the animal.
By storing the position values from the initial recognition sequence of a respective animal and controlling the scanning head so as to start subsequent recognising operations taking account of the stored information, i.e. in practice closer to the udder, the recognising sequence may be shortened in an advantageous way with respect to later milking operations.
In the event that the teats are not found during such a shortened sequence within a predetermined time period for one reason or the other, the system is preferably adapted to start over again using an initial position according to the above, which is adapted to investigate all new relevant animals.
By updating position values during subsequent recognising sequences, altered teat positions and other changes are dealt with.
The invention also comprises a milking robot including the conventional means for carrying the scanning head, a drive means therefore, teat cup arrangements, means for handling milk and other fluids such as disinfectants, and a control unit capable of controlling the operation of the robot.